Precision Fabricator Boosts 100 Percent Parts Inspection Program W/ Height Gage

For a design engineering, precision machining and fabrication company that provides its customers with 100 percent parts inspection in order to live up to its reputation for high quality production, 41-year-old Amherst Tool and Automation Co., Inc. (Amherst, New York) needs to perform its inspection with great speed. The company makes precision tools, dies, gages, and fixtures, as well as automated special machinery and a range of custom machinery. It also provides engineering services.

Recently, Amherst has been able to attain much faster inspection with the addition of a new and highly versatile Fowler/Sylvac Z-Cal height gage from Fred V. Fowler Co., Inc. (Newton, Massachusetts). One of the key advantages of this gage is "its ability to be used both in the inspection laboratory and directly at the lathes, grinders and other milling machines producing the parts," says Michael Kretz, vice president of plant operations.

Often, these inspections are performed up to ten times more rapidly than before on smaller parts, thanks to the new height gage, he says. The height gage has a 12-inch measurement envelope.

Inspector Robert Schuler cites a typical measuring routine to illustrate this point. "When you want to assess a whole diameter," he says, "all you have to do is hold on the bottom diameter, and the Z-Cal automatically reads the lowest portion of that diameter. Then you raise the pointer, and you obtain the actual diameter on top of the part. It tells you the height if you zero set from the table, giving you the reading from the table to the center of the hole automatically.

"If I have to take a diameter reading on a lathe or grinder, I just bring the gage right to the machine and measure, instead of taking the part to the gage," he says. "And it gives a true reading."

The new instrument is particularly useful for close tolerances to 0.0001 inch, which constitute half of the workload in measurement and inspection, Mr. Schuler says. The gage's resolution is 0.0005-0.00005 inch, and it is easier to use than the previous instrument, which required pressing an airlift. It is also lighter in weight (11.6 lbs) and therefore easier to move around, he adds. It uses a 3-mm probe, and it makes all measurements (height, depth, slot, ID and OD and distance between centers) within an accuracy of 6 microns for the 12-inch range instrument used by ATA, Fowler claims.

Mr. Kretz says the company's four-year program has made it ISO 9002 compliant since 1996, from raw materials through shipping final product. He also indicates that he feels ATA has a "top-notch calibration program for both its tools and gages."

The company is entirely climate-controlled to enhance close tolerance machining operations, and its inspection and grinding areas are isolated from general machining and assembly areas to prevent contamination.